Glow-in-the-dark 'Nook' E-Reader launched

Barnes & Noble Inc. tackled one of the shortcomings of black-and-white e-readers with a screen that lights up so it can be read in the dark...

Barnes & Noble Inc. tackled one of the shortcomings of black-and-white e-readers with a screen that lights up so it can be read in the dark.

WATCH: First Look-Nook Simple Touch with Night-Glow

E-readers with black-and-white screens, made by Barnes & Noble, Amazon, Sony and others, are easily readable in bright light but don't come with their own light sources and can't be read in darkness. The ones with color screens, such as the Kindle Fire and Nook Tablet, do have their own light sources but are barely legible in sunlight.

The new "Nook Simple Touch with GlowLight" has a standard black-and-white screen, but an array of light-emitting diodes inside the frame spreads a glow over the page with the help of an invisible light-guiding layer.

The ability to read books in bed without disturbing a partner by turning on a bedside lamp has been a top request from customers, said Jamie Ianonne, the head of Barnes & Noble's digital division.

The model will be in stores early next month and cost $139, The New York-based chain said.

The cheapest Nook with a color screen costs $169. Barnes & Noble is keeping its non-lit black-and-white Nook in the lineup at $99.

Black-and-white e-readers can't be lit the same way color screens are. Color screens are translucent and require a "backlight" shining through them to look clear and legible. Black-and-white screens, on the other hand, are more like paper. They aren't translucent, so any lighting has to come from above.

Sony Corp., which pioneered the black-and-white e-reader, introduced a model with a built-in light in 2008, but the lighting was poor. The model's screen was much brighter on the edges. The light-guiding layer also made the screen less clear in all types of light. The model was soon retired.

Barnes & Noble developed its own technology to deal with the problem, and has filed for patents to protect it. The lighting is even over most of the page, but noticeably brighter along the top of the page where the LEDs are housed.

The light will sap some of the battery power. With no lighting, the reader will last for two months of 30 minutes of reading per day. With the light in use, it will last a bit more than a month, Ianonne said.